Specifications

DMD20/20LBST Universal Satellite Modem User Interfaces
MN-DMD20-20LBST Revision 14 4–16
Closed Net:
All possible combinations allowed, however, a DVB setting
requires the DVB network spec.
STRAP CODE {Refer to Strap Code Guide, Appendix H}
The Strap Code is a quick set key that sets many modem
parameters. Consult the strap code guide for available strap
codes. Parameters set by strap code:
Data Rate
Inner Code Rate
Satellite Framing
Scrambler
Drop and Insert
Outer Code Rate (Reed-Solomon)
Modulation
Network Spec
IF (menu)
FREQUENCY (MHz) {50 – 90 MHz, 100 – 180 MHz, or 950 - 2050 MHz}
{950 – 2050 MHz} for LBST}
Allows the user to enter the Modulator IF Frequency in 1 Hz
increments.
DWNLNK FREQ (MHz) Displays the input frequency into the LNB from the satellite, also
referred known as Satellite downlink frequency. The user must
enter the LNB LO and OSC SIDEBAND of the LNB before using
this menu. The DOWNLINK FREQUENCY is a calculated
measurement of both the LNB LO and OSC SIDE BAND. Once
the menus are entered correctly, the user can control the
downlink Frequency from this menu.
SPECTRUM {NORMAL INVERTED}
Allows the user to invert the direction of rotation for PSK
Modulation. Normal meets the IESS Specification.
LBST: Spectral inversion may be required if the LNB LO is
higher in frequency than the LNB input frequency from the
satellite. When LNB LO is higher in frequency than the LNB
input frequency, this creates a spectral inversion and the IF
Spectrum must be inverted to compensate for the inversion.
MODULATION {QPSK, BPSK, OQPSK, 8PSK, 16QAM, 8QAM}
Allows the user to select the demodulation type.
SPECTRAL MASK {Intelsat 0.35, DVB 0.35, DVB 0.25, DVB 0.20}
Allows the user to set the spectral shape of Tx Data Filter.
SWEEP RANGE (kHz) {±0 to 255 kHz}
Allows the user to set the acquisition range for the demodulator
SWEEP DELAY (Sec) {0.0 – 6553.5 sec}
Allows the user to set the reacquisition delay time in 1/10
th
second increments.